The present invention is directed to an article transfer mechanism, such as a 90.degree. pusher, which is adapted for use in a wide variety of individual section machines (so-called I.S. machines). In particular, the invention is directed to a 90.degree. pusher that moves at an angular speed profile is governed by a user-modifiable algorithm to tailor the angular speed profile according to I.S. production parameters.
So-called 90.degree. pushers are known in the art, examples of which are found in U.S. Pat. Nos. 3,779,362 and 4,203,752. (The 90.degree. pushers are also known in the art as pushout, sweepout or take-away devices.) The 90.degree. pusher transfers articles, such as newly formed glass containers, from the dead plate of an I.S. machine to a moving conveyor. Typically, plural pusher stations are employed, each of the stations being operated in a predetermined timed sequence. The sequence of operation of the pusher stations may be governed by a drum and cam mechanism, or by a timing disk and electric switch network. In addition, the motion profile of the 90.degree. pusher as it moves through its arc can be governed by a mechanical cam. The cam determines the speed of rotation of the pusher at various positions along the arc, known in the art as the speed or velocity profile of the pusher. Different articles and conveyor speeds frequently require different pusher speed profiles to insure a smooth transfer of the article to the conveyor.
In U.S. Pat. No. 4,203,752 to Becker, the speed profile of the pusher arm of the 90.degree. pusher is determined by an electric motor driving a crank and rocker mechanism. Mechanisms of this type have interrelated mechanical parts which are subject to malfunction and wear. However, mechanisms of this type have some provision for adjustment of the speed profile of the pusher arm by variations in the voltage provided to the electric motor driving the arm.
In an improvement on the system described in the Becker patent, plural pusher stations are electronically controlled in a predetermined timed sequence. The angular speed profile of the pusher arm is determined by a PROM or other programmable electronic element in the pusher station electronic circuit. A system of this type is described in the co-pending application of Newkirk, Ser. No. 348,154, which issued as U.S. Pat. No. 4,923,499 and which is a continuation of abandoned application Ser. No. 206,907 which is also a continuation of the abandoned parent application Ser. No. 216,334 all assigned to the assignee of the present invention. In this system, a stepping motor is utilized to rotate the pusher arm. The stepping motor advances in rotary or angular increments which causes stepwise rotation of the pusher arm. The angular speed profile of the pusher arm then is determined by the dwell time between steps of the stepping motor.
In U.S. Pat. No. 4,923,499, data stored in the PROM corresponds to the number of steps to be counted up to by a speed counter before an index signal is sent to the stepping motor control circuit. The stepping motor control circuit indexes or steps the stepping motor in response to the index signal. The rate at which the index signals are sent to the stepping motor control circuit determines the speed profile of the motor and the pusher. The data in the PROM also controls the number of motor steps based upon a one-to-one correspondence to the number of data words in the PROM. This system is described more fully in U.S. Pat. No. 4,923,499, particularly at Col. 7, line 57 to Col. 12, line 49 and accompanying FIGS. 14-16, which disclosure is incorporated herein by reference. Other examples of electronic controls for 90.degree. pushers are shown in U.S. Pat. Nos. 4,313,750 and 4,409,013.